Of mammoths, microbes and molecules, paleometagenomes from the past

大量令人信服的证据表明，行星气候系统正朝着过去12万年来从未有过的状态发展。这些变暖趋势对“整个生态系统”（即微生物，动物，花卉和昆虫）多样性的影响仍然未知。检验这一点的一种方法是回顾过去。大约11,000年前，100多种大型哺乳动物和鸟类在北美灭绝。虽然这些损失的确切原因尚不清楚，但考虑到我们迅速变暖的北极，它们的潜在后果在今天仍然非常重要。生物群将如何应对迅速变暖的北方？解决这个问题的一种方法是评估他们在过去是如何应对之前的气候变化的，那些同样或更剧烈的变化。利用从化石遗骸中收集到的遗传特征（包括哺乳动物和微生物），我们将研究种群如何应对过去类似的气候变化，并利用这些信息帮助我们为不久的将来即将到来的损失做好准备。有了这些数据，我们就可以开始解决一些问题，比如为什么有些物种灭绝了（猛犸、乳齿象、树懒、马），而另一些物种却存活了下来（野牛、熊）？虽然许多人认为气候是这些损失的直接原因，但其他人认为人类（大型狩猎者）在他们的最终灭亡中发挥了关键作用。也许有效的人口规模是如此之小后冰川时期，他们实际上是在一个“临界点”，人类处理的最后一击。

Abundant and compelling evidence indicates that the planetary climate system is moving toward states not equalled in the last 120,000 years. The implications of these warming trends on ‘whole-ecosystem’ (i.e microbial, faunal, floral and insect) diversity remain unknown. One way to test this is to look back in time. Approximately 11,000 years ago more than 100 species of large mammals and birds went extinct in North America. While the precise causes of these losses remains unclear their underlying consequences remain exceptionally pertinent today, given our rapidly warming artic. How will biota respond given the rapidly warming north? One way to address this is to evaluate how they responded in the past, to prior climatic shits, ones that were equally or more drastic. Using genetic signatures gleaned from fossil remains, (both mammalian and microbial) we will investigate how populations responded to similar climatic shifts in the past and use this information to help prepare us for looming losses in the near future. With these data we can begin to address questions such as why was it that some went extinct (mammoth, mastodons, sloths, horses) while others persisted (bison, bears)? While many argue that climate was the direct cause of these losses, others have suggested that humans (big game hunters) played a critical role in their final demise. Perhaps effective population sizes were so small post glacial time periods that they were effectively at a ‘tipping point’, and that humans dealt the final blow.